席雅允, 刘娟红, 程立年. 荷载与硫酸盐耦合作用下铁尾矿粉混凝土 性能劣化机理研究[J]. 工程科学学报. DOI: 10.13374/j.issn2095-9389.2023.09.13.006
引用本文: 席雅允, 刘娟红, 程立年. 荷载与硫酸盐耦合作用下铁尾矿粉混凝土 性能劣化机理研究[J]. 工程科学学报. DOI: 10.13374/j.issn2095-9389.2023.09.13.006
Study on the deterioration mechanism of iron tail powder concrete under the coupling action of load and sulfate…[J]. Chinese Journal of Engineering. DOI: 10.13374/j.issn2095-9389.2023.09.13.006
Citation: Study on the deterioration mechanism of iron tail powder concrete under the coupling action of load and sulfate…[J]. Chinese Journal of Engineering. DOI: 10.13374/j.issn2095-9389.2023.09.13.006

荷载与硫酸盐耦合作用下铁尾矿粉混凝土 性能劣化机理研究

Study on the deterioration mechanism of iron tail powder concrete under the coupling action of load and sulfate…

  • 摘要: 铁尾矿粉作为矿物掺合料应用于混凝土有助于固废高值化利用和节能减排,而关于铁尾矿粉混凝土耐久性能的研究,大多只考虑了单一条件或者加速条件环境,其在多种环境耦合下的劣化特征尚未得到探究。本文以相对动弹性模量、质量损失率为性能指标,研究荷载-干湿循环-硫酸盐耦合作用下铁尾矿粉混凝土劣化过程,探究铁尾矿粉掺量、荷载率对铁尾矿粉混凝土内部劣化的影响,结合扫描电镜(SEM)、X-ray 衍射分析(XRD)、压汞(MIP)等微观手段揭示铁尾矿粉混凝土在耦合作用下损伤劣化机理。结果表明:荷载的施加使试块内部微裂纹宽度和数量增加,持续的钙溶蚀造成浆体孔隙率增大,形成更多连通通道;耦合作用使得铁尾矿粉混凝土内部损伤不断累积,在微观上表现为结构的疏松和裂缝的衍生扩展,在宏观上表现为力学性能的衰减和整体结构完整性的下降。

     

    Abstract: The application of iron tailing powder to concrete as a mineral admixture is conducive to high value utilization of solid waste and energy saving and emission reduction. However, most studies on the durability of iron tailing powder concrete only consider single conditions or accelerated conditions, and its deterioration characteristics under multiple environmental coupling have not been explored. In this paper, the relative dynamic elastic modulus and mass loss rate are used as performance indexes to study the deterioration process of iron-tailing powder concrete under load-wet-cycling-sulfate coupling, and explore the influence of iron-tailing powder content and load rate on the internal deterioration of iron-tailing powder concrete. By means of scanning electron microscopy (SEM), X-ray diffraction analysis (XRD) and mercury injection (MIP), the damage and deterioration mechanism of iron tail powder concrete under coupling action was revealed. The results show that the application of load increases the width and number of microcracks inside the test block, and the continuous calcium dissolution results in the increase of slurry porosity and the formation of more connected channels. The coupling effect makes the internal damage of iron tail powder concrete accumulate continuously, which is manifested in the porosity of structure and the derivative expansion of cracks on the micro level, and the attenuation of mechanical properties and the decline of the overall structural integrity on the macro level.

     

/

返回文章
返回